Backbones are an important part of the anatomy of many animals, including humans. The term 'BACKBONE' can refer to three different structures: VERTEBRAE (9 letters), spines (6 letters), and chines (6 letters). VERTEBRAE are the bones that make up the spine in humans and other vertebrates. Spines are the sharp, rigid projections that extend from the back of some animals, such as porcupines. Chines are the ridges along the sides of a fish's body. All three of these structures provide support and stability to the body and are collectively referred to as backbones.